Electro-optical/infrared (EO/IR) sensors and photovoltaic power sources are being developed for a variety of defense and commercial applications. One of the critical technologies that will enhance both EO/IR sensor and photovoltaic module performance is the development of high quality nanostructure-based antireflection coatings. In this paper, we review our work on advanced antireflection struc...

Establishing reliable and efficient antireflection structures is of crucial importance for realizing high-performance optoelectronic devices such as solar cells. In this study, we provide a design guideline for buried Mie resonator arrays, which is composed of silicon nanostructures atop a silicon substrate and buried by a dielectric film, to attain a superior antireflection effect over a broad...

GaN nanostructures with various effective refractive index profiles (Linear, Cubic, and Quintic functions) were numerically studied as broadband omnidirectional antireflection structures for concentrator photovoltaics by using three-dimensional finite difference time domain (3D-FDTD) method. Effective medium theory was used to design the surface structures corresponding to different refractive ...

Reflection occurs at an air–material interface. The development of antireflection schemes, which aims to cancel such reflection, is important for a wide variety of applications including solar cells and photodetectors. Recently, it has been demonstrated that a periodic array of resonant subwavelength objects placed at an air–material interface can significantly reduce reflection that otherwise ...

Tradional antireflection coatings composed of dielectric layers usually require the thickness to be larger than quarter wavelength. Here, we demonstrate that materials with permittivity or permeability dominated by imaginary parts, i.e. lossy or gain media, can realize non-resonant antireflection coatings in deep sub-wavelength scale. Interestingly, while the reflected waves are eliminated as i...

Reduction in surface and interface reflectance via the integration of subwavelength nanostructures in flexible polymer packaging material combined with incorporation of dielectric nanoislands into a conventional two-layer antireflection coating has been demonstrated, analyzed and optimized. Transmittance measurements of moth-eye textured polymer packaging sheets with different tapered pillar he...

Designs of multilayer antireflection coatings made from co-sputtered and low-refractive-index materials are optimized using a genetic algorithm. Co-sputtered and low-refractive-index materials allow the fine-tuning of refractive index, which is required to achieve optimum anti-reflection characteristics. The algorithm minimizes reflection over a wide range of wavelengths and incident angles, an...

Electromagnetic metamaterials have emerged as a new class of effective media where exotic properties are determined from structural geometry and dimensions of the basic building blocks, or meta-atoms. Through such a bottom-up approach, metamaterials have found applications in the construction of terahertz functional devices and components with unprecedented performance. In this paper, we numeri...

We propose an effective admittance (EA) method to design antireflection structures for two-dimensional photonic crystals (PCs). We demonstrate that a compact and efficient antireflection structure, which is difficult to obtain by the conventional admittance matching method, can be readily designed by the EA method. The antireflection structure consists of an air slot resonant cavity that is con...